Steam wand

ABSTRACT

A steam wand assembly for an espresso machine has features for preventing overheating of the tip of the steam wand. In a first aspect there is provided a steam wand device comprising a metallic main body tube, a steam hose that passes through the tube, the steam hose also passing through a flexible spacer that is within the tube. In a further aspect there is provided a steam wand device comprising a main body tube having a metallic primary tube and a metallic tip, the primary tube and the tip being attached to one another by a polymeric steam nozzle, the nozzle having a central bore that extends from an inlet adjacent to a lower end of a steam hose to an exit opening.

FIELD OF THE INVENTION

The invention relates to an apparatus for steaming beverages and moreparticularly to a steam wand that is attached to a device with a steamboiler such as an espresso making machine.

BACKGROUND OF THE INVENTION

The present invention provides a variety of alternatives andimprovements to conventional steam wand technology.

OBJECTS AND SUMMARY

It is an object of the invention to provide a steam wand or steam wandassembly with improved performance benefits, or new functionality, orsafety features.

Accordingly, there is provided a steam conveyor or steam wand assemblythat is supported by a ball joint but guided to achieve a restrictedrange of motion in a home position.

In other embodiments of the invention a steam wand assembly thatcooperates with a switch that provides location information to acontroller. The controller may use the location information for avariety of purposes such as initiating a steam purge cycle, preventingunsafe use of the steam wand or providing display information.

In other embodiments of the invention, the steam wand comprises aninternal hose that carries steam to a tip of the steam wand.Improvements prevent the hose from transferring heat to the main bodytube, by avoiding contact with the interior side wall of the wandassembly.

In further embodiments of the invention, a steam wand is biased toreturn to a home position, the bias force that accomplishes same beingresisted by a dampener that regulates the speed at which the wandreturns to the home position.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

In order that the invention be better understood, reference is now madeto the following drawing figures in which:

FIG. 1 is a perspective view of a steam wand assembly and supportfixture.

FIGS. 2(a)-(c) illustrate the movement of the neck of a steam wandwithin its guide.

FIGS. 3(a)-(c) illustrates the engagement and disengagement of a steamwand ball fin into a co-operating slot.

FIG. 4 is a perspective view, partially sectioned illustrating theengagement of a steam wand ball fin in a slot.

FIG. 5 is a perspective view, partially sectioned illustrating themovement of a steam wand having a ball, fin and slot arrangement.

FIG. 6 is a cross-sectional view of a steam wand, switch and switchactuator.

FIG. 7 is a cross-sectional view of a steam wand, switch and switchactuator.

FIG. 8 is a cross sectional view of a steam wand ball and co-operatingfriction cheeks.

FIG. 9 is a cross sectional view of a steam wand ball and co-operatingfriction cheeks.

FIG. 10 is a perspective view of another embodiment of a steam wandhaving a pivoting bracket and torsion spring or coil.

FIG. 11 is a perspective view of the device depicted in FIG. 10illustrating the use of a dampener in conjunction with a torsion spring.

FIG. 12 is a side elevation of the steam wand and dampener depicted inFIG. 11.

FIG. 13 is a cross sectional view of the steam wand depicted in FIG. 12illustrating an insulating spring.

FIG. 14 is an exploded perspective view of the lower end of a steamwand, showing its steam nozzle and tip.

FIG. 15 is a cross sectional view of the lower end of a steam wand,nozzle and steam wand tip.

FIG. 16 is a perspective view of an espresso machine having a steam wandassembly.

FIG. 17 is a rear perspective view of a steam wand assembly of the typedepicted in FIG. 16.

FIG. 18 is a cross-sectional view of the steam wand assembly depicted inFIG. 17.

FIG. 19 is a cross-sectional view of the steam wand assembly depicted inFIG. 17, in an extended position.

FIG. 20 is a perspective view of an insulating sleeve for a steam wand.

FIG. 21 is a cross-sectional view of the sleeve of FIG. 20.

FIG. 22 is another embodiment of an insulating sleeve for a steam wand.

DETAILED DESCRIPTION

As shown in FIG. 1, a steam wand assembly 100 includes a steam wand 101that is retained by a support fixture 102. The wand may be articulatedor stationary. The wand has a main body tube 120 that may be formed fromone or multiple sections. Because the main body tube is generallymetallic and steam passes through it, it is an advantage to insulate thetube from the steam. In this example, the steam wand 101 is articulated,having a ball 103 at one end that is received by a socket 104 that formspart of the support fixture 102. An opposite end of the wand is formedby a removable wand tip 105. The tip is formed, in part, from the mainbody tube. A ring-like handle 106 is located between the ball 103 andthe tip 105. The wand may be straight or bent. The current example isbent in two locations 121, 122.

The ball 103 may be attached to or formed integrally with a neck 107optionally having a smaller diameter than the remainder of the wand 101.In this example, the neck 107 passes through a guide 108 in which isformed an opening 109 through which the neck 107 extends.

As further shown in FIG. 1, the wand 101 has a home position 111. In thehome position, the wand tip 105 is at its closest distance to the uppersurface of the drip tray, grating or other support surface 110 of thedevice to which it is attached. The wand also has an extended positionor position of normal use 112. In the extended position 112, the wand isfree to move from side to side 113.

As shown in FIG. 2, the guide 108 determines the limits of movement ofthe neck 107 and therefore the wand 101. As shown in FIG. 2(a) theguide's opening 109 is generally triangular. Each of the three corners201 are preferably radiused to conform to the external radius of theneck 107. In this example, the side edges 202 of the opening are convex,the middle of each side edge extending toward the centre of the opening109. The front edge 203 is concave, its middle extending slightly awayfrom the centre of the opening 109.

FIG. 2(a) represents the position of the neck 107 when in a homeposition. In the home position, the wand 101 is retracted to its maximumextent with respect to the device that supports the fixture 102. Thehome position is shown by the dotted line representation 111 in FIG. 1.

In some examples, the neck may be vertical or near vertical in the homeposition. In the home position, steam optionally passes through the wandonly for the purposes of cleaning or purging it. In the home position,the wand tip 105 is at its closest point to the device's drip tray,grating or other supporting surface 110. FIGS. 2(b) and (c) representthe position of the neck with respect to the guide when the wand is inan extended position 112 (see FIG. 1). In the extended position, theneck and therefore the wand can be pivoted from side to side 113. Theextension of the wand is limited by the contact of the neck against thefront edge of the opening as shown in FIG. 2(c).

FIG. 2 also illustrates that the wand's ball 103 is provided with aguide fin 203, as will be explained.

As suggested by FIGS. 3, 4 and 5, the support fixture 102 includes asocket 301 for retaining the wand's ball 103. As suggested by FIG. 3(a),in the home position, the ball's fin 203 is retained by a radiallyextending slot 302 that extends away from the socket 301. Because theball's fin 203 is retained by the slot 302, the ball and therefore thewand 101 is restrained from rotation or side to side motion 113. Asshown in FIG. 3(b) when the wand is extended toward its position of use112, the fin 203 exits the slot 302. This allows the wand 101 to berotated, also permitting side to side motion 113 as suggested by FIG.3(c).

The capture of the fin 203 by the slot 302 is also shown in FIG. 4. Notethat the wand 101 is, in this example, essentially vertical andtherefore restrained in its movement by either or both of the guide 108and the interaction between the fin 203 and the slot 302. The upper part401 of the slot may be enlarged to receive the head of a switch actuator605 as shown in FIG. 6.

As shown in FIG. 5, extending the wand 502 into its position of use 501frees the fin 203 from the slot 302. It will be appreciated that FIGS. 4and 5 are partially sectioned allowing the interior of the socket 301and slot 302, 401 to be better illustrated.

As shown in FIG. 6, the pivoting ball 103 and its locating fin 203cooperate with a rotating or pivoting switch actuator 601. The switchactuator pivots about a generally horizontal axis 602 and its biasedinto the lower orientation depicted in FIG. 6 by a torsion spring 603that preferably surrounds or encircles the pivot axis 602. In the wand'sextended position as shown in FIG. 6, the head 604 of the actuator isextended and in contact with the proximate flat surface of the fin 203.An opposite end of the actuator 601 forms a mechanical contact 605. Whenthe wand 101 is returned to the home position as shown in FIG. 7, theactuator 601 rotates, driving the contact 605 into a closing engagementwith a switch, such as a micro switch having a flexible of leaf contact701. When the switch 702 is closed, a signal or switch state 703 isdetected by the device's controller or microprocessor control unit 704.The signal 703 (representative of the wand being in the home) positionis utilised by the controller 704 to perform one or more of a variety offunctions. For example, the controller 704 can use the signal 703 toinitiate a purge or cleaning cycle of the wand 705. The controller 704can also use the location information signal 703 to initiate a displayor audible warning from the device's graphic and audio user interface706. The signal 703 may also be used for other functions 707.

As shown in FIG. 7, the ball 103, and neck 107 have a central passageway708 that leads into an interior 709 of the wand 101. The hose 711 goesthrough the passageway into the interior 709. The hose is preferably anon-reactive flexible polymer such as PTFE (Teflon®). The major extentof the wand's body comprises a hollow metal tube 710. The hose 711carries steam or a steam air mixture through the ball 103, neck 107 andwand 101. The ball's entry opening 712 may be circumferentially taperedor chamfered to reduce torsion stress on the hose 711 and to betteraccommodate the flexing of the hose 711 when the wand 101 is moved fromone position to another.

As shown in FIG. 8, in some embodiments, the wand's ball 103 may befrictionally retained by a pair of opposing cheeks 801, 802. Each cheek801, 802 has a ball engaging concave surface 803. As shown in FIG. 8,one cheek is fixed to a cup 809 and one of the cheeks 804 is carried bya stem 805. The stem 805 is surrounded by a pair of nested or concentriccompression springs 806, 807. In this example, two springs 806, 807 areprovided to increase the force against the ball 103. The cross sectionaldiameter or gauge of the inner spring 806 is preferably smaller than thecross sectional diameter of the outer spring 807. The cheek and springassembly shown in FIG. 8 is retained by a pair of opposing cups 808,809. The arrangement of concentric or nested coil springs 806, 807provides significant force against the ball 103, in a compact space.

In the example of FIG. 9, the wand's ball 103 is engaged by two similarcheeks 901, 902. Each cheek has a stem 903 that extends toward itsrespective retainer or cup 908 and each stem is surrounded by a singlecompression spring 903.

As shown in FIG. 10, in some embodiments, an upper end of the wand 1000is affixed to a pivoting bracket 1001 instead of a ball. The bracket1001 has parallel and spaced apart sides 1002, 1003. The sides 1002,1003 are pivotally retained by parallel walls of the retaining fixture1004, 1005. A pivot shaft 1006 extends between the side walls 1004, 1005and carries the sides 1002, 1003. A coil or torsion spring 1007 wrapsaround the shaft 1006 and is used to bias the bracket and its wand 1000into the home position.

As shown in FIG. 11, one side 1002 of the bracket 1001 extends towardand affixes to or comprises an arcuate gear section 1100. Accordingly,the gear section 1100 rotates in unison with the bracket about the pivotshaft 1006. The gear teeth 1101 of the gear section engage a cooperatingpinion 1102 carried by a rotary dampener 1103. The dampener 1103 isstationery. The dampener 1103 moderates the velocity of the wand 1000,particularly toward the home position under the influence of the torsionspring 1007.

As shown in FIG. 12, the arcuate gear section 1100 terminates, at oneend, with and actuates a switch actuator portion 1200. The switchactuator portion of the gear section makes contact with a switch such asa micro switch 1201 when the wand 1000 is in the home position. In otherpositions, the actuator portion 1200 of the gear section 1100 does notcontact the switch 1201. In this way, the home position is associatedwith (for example) the closure of the switch 1201, which closure can bedetected by the devices' controller and utilised in the manner suggestedby FIG. 7.

FIGS. 13, 14 and 15 illustrate an exemplary embodiment of a steam wandconstruction. As shown in FIG. 13, a steam wand 1300 has a main bodytube 1301, and is bent in two locations, for ease of use. The tube isformed in sections preferably constructed from stainless steel. Here,one section is the primary tube 1350 and the tip section 1306. The upperend of the tube 1301 is affixed to (for example) a bracket or ball aspreviously described. The upper end 1302 of the main body 1301 admits asteam hose 1303, preferably a non-reactive flexible polymer such asPTFE. The polymer forms a first insulation between the steam and thetube 1301. The lower end 1304 of the main body tube 1301 is internallythreaded and thereby affixed to co-operating threads or otherwise fittedto the exterior of a polymeric (for example PTFE) steam nozzle 1305. Alower end of the steam nozzle is also externally threaded so as toreceive the co-operating internal threads of a metallic steam wand tip1306. In other embodiments, the main body tube 1301 is flexible. Thewand tip has an exit opening 1307 through which protrudes the lower end1308 of the steam nozzle 1305. The steam nozzle has an optionalcircumferential flange 1309 that separates the lower end of the mainbody tube from the upper end of the tip 1306. The steam nozzle 1305 hasa central bore 1310 with an uppermost inlet that communicates with thelower end of the hose 1303. The lower end 1311 of the hose 1303 iscompressed or stabilised against the interior of the tip connectorcomponent by an internal and hollow rivet 1341 that fits into the lowerend of the hose. The lower end of the hose is encircled by a tipconnector 1312 that is carried within a recess in the upper part of ahose connector 1313. The lower part of the hose connector 1313 forms abore that receives the upper part 1314 of the steam nozzle 1305. A seal1315 is interposed between the hose connector 1312 and the tip connector1312. A second seal 1316 is interposed between the upper part of thesteam nozzle 1314 and the lower bore of the tip connector.

Thus, the hose 1303 extends from close to the upper opening of the steamnozzle 1305 to a location 1317 external to the wand 1301. The hose 1303passes through an insulation spring or coil 1320 forming an elongatedspacer within the wand body 1301. In this example, the spacer or coil1320 is continuous, having a generally constant pitch.

The hose has an extent outside the want and an extent internal to thewant or its tube 1301. For the purpose of preventing contact between thehose and the metallic tube, various second insulations are proposed.These insulations are elongated spacers and capable of protecting thefill (or any portion) of the internal extent of the hose. In the exampleof FIG. 13, the second insulator is in the form of a non-metallic coil,helix or spring. The effective outside diameter of the spacer 1320alternates between each turn of the coil. Turns of a larger diameter1321 alternate with turns of a smaller diameter 1322. The largerdiameter turns 1321 make contact, as required, with the interior of themain body tube 1301. The smaller diameter turns 1322 make contact withthe outside of the hose 1303. In this way, the hose is prevented frommaking direct contact with the interior of the primary tube 1350 andthereby losing heat to it.

In the example of FIG. 13, the primary tube has two pairs of opposingthrough openings 1323, 1324. One of the pairs 1323 is used to receiveintegral rivets 1325 that form a terminal end of a handle such aring-like handle 1326 fabricated from stainless steel or other metal.The rivets 1325 are deformed by a tool that is inserted through theopposing through openings 1324. Other methods of providing a handle maybe used.

As shown in FIG. 14, a “C” clip or other retainer 1401 is accessiblethrough an opening or slot 1402 in the hose connector 1310 prevents theinadvertent withdrawal of the tip connector 1312. Also shown are thenozzle seals 1403, 1404 that are carried by the grooves 1405, 1406 onthe upper and lower sides of the external flange 1309. The upper seal1403 seals the lower end of the main body tube against the steam nozzle1305 and the lower seal 1404 seals the upper end of the wand tip 1306against the steam nozzle 1305.

As shown in FIG. 15, there is a small gap 1501 located between the lowerextremity of the tube 1303 and the adjacent upper extremity and bore1310 of the steam nozzle 1305. The lower end of the steam nozzle is alsoshown as having one or more discharge openings 1502, 1503, as required.The lower end of the steam nozzle may also have a groove for carrying aterminal seal 1504 that seals against an inside diameter or surface 1505of the steam wand tip 1306.

As shown in FIG. 16, an espresso making machine 1601 has a platform ordrip tray 1602 that is located below the device's group head 1603 andoptional coffee grinder outlet 1604. In preferred embodiments, the steamwand is operable in the lower most or home position illustrated in FIG.16. In other embodiments, the wand may be disabled when it is in thelower most or home position as shown in FIG. 16.

As shown in FIG. 17, a steam wand assembly 1701 has a steam wand 1702that is carried by a wand pivot 1703. The wand pivots 1703 is carried byand pivots about a pivot bracket 1704. A torsion spring or other biasdevice 1705 is attached to the pivot bracket 1704 and urges the wandpivot 1703 and therefore the wand 1702 toward the home position depictedin FIG. 16. The flexible polymeric steam tube 1706 passes between thepivot bracket 1704 and the wand pivot 1703.

As suggested by FIGS. 17 and 18 the pivot bracket 1704 is rigidlyaffixable to the chassis or a chassis component of the device 1601. Inthis example, the pivot bracket 1704 carries a leaf spring 1707 having aradius or rounded tip 1802. The tip is received by one or more detentslocated on the periphery of a smooth external surface 1803 of the wandpivot 1703. The rounded portion of the wand pivot 1803 extends from afront surface 1804 of the wand so as to occupy the gap between the frontof the wand 1804 and an adjacent external part of the chassis 1805. Asimilarly rounded portion of the wand pivot 1806 extends from the rearsurface of the wand 1807 toward and past an adjacent rearward edge ofthe chassis 1808. The rounded portions 1806, 1803 occupy the forward andrear gaps around the wand pivot so that a finger is not trapped orpinched between the wand and the chassis when the wand is pivoting. Inthe example of FIG. 18, the pivot point of the wand 1809 passes througha centre of the wand pivot. The lateral sides of the wand pivot are flatand generally parallel. The co-operation between the leaf spring 1707and the detents 1803 allow the wand to assume one, two or more stableorientations. Other aspects of the wand including the construction ofthe insulating tip 1810 and insulating spring 1811 are similar to thosepreviously disclosed.

As shown in FIG. 19, the pivot bracket 1901 may carry a sensor, switchor micro switch 1902 that is used to provide wand position informationto the device's processor 1607. In this example, a rearward extension ofthe wand pivot 1903 makes contact with the switch or its actuator 1904when the wand is in the home position, but not when it is in theextended position depicted in FIG. 19. Note that in this example, theextended position is defined by the location of the leaf spring in thedetent 1803. The rearward extension 1903 of the wand pivot 1703 may alsobe used as a limit to the forward extension of the wand, by abutting andinterfering with a part of the chassis 1905 adjacent to the wand pivotand located behind the wand.

As shown in FIG. 20, the coil depicted, for example in FIGS. 13, 15, 18and 19 can be formed from a flexible and heat resisted polymer as shownin FIGS. 20 and 21. In the examples of FIGS. 20-22, the sleeve 2000 isintended to be used within a wand for the purpose of inhibiting contactbetween the tube carrying steam and the inner wall of the tube 1301. Thesleeve 2000 in this example, comprises a tube 2001 having variousprojections, spacers or tabs 2002 along its length. In this example, theprojections 2002 are provided in pairs 2002, 2003. Pairs are spacedapart from one another along the length of the tube. Each projection orwing comprises a rounded or a smooth exterior. As shown in FIG. 21, theprojections in each pair 2002, 2003 are separated from one another by anarch shaped notch 2100. As suggested by FIG. 20, the tube may have oneof more longitudinal ribs 2004 extending along all or part of the lengthof the tube. The tube has a central opening 2005 for receiving the steamtube.

As shown in FIG. 22, a sleeve 2200 may also comprise a skeletal tubehaving, for example, a pair of longitudinal ribs 2201, 2202. The tworibs 2201, 2202 are parallel and spaced apart. The two ribs areinterconnected by arches that alternate along the length of the ribs.Alternating arches 2203, 2204 are spaced apart and located along thelength of the ribs. The two ribs 2201, 2202 define a plane. Arches 2203on one side of the plane extend downwardly or in one direction andarches 2204 on the other side of the plane extend upwardly or in theother direction. Each arch is associated with a pair of lateralextension tabs 2205, 2206. Each arch is also associated with a pair ofparallel and spaced apart fingers 2207, 2208, the fingers extending awayfrom the arch in the same direction as the arch extends away from theparallel ribs. In the example of FIG. 22, the arches (extending ineither direction from the ribs) are evenly spaced from one another andalternating.

Although the invention has been described with reference to specificexamples, it will be appreciated by those skilled in the art that theinvention may be embodied in many other forms.

As used herein, unless otherwise specified, the use of the ordinaladjectives “first”, “second”, “third”, etc., to describe a commonobject, merely indicate that different instances of like objects arebeing referred to, and are not intended to imply that the objects sodescribed must be in a given sequence, either temporally, spatially, inranking, or in any other manner.

Reference throughout this specification to “one embodiment” or “anembodiment” or “example” means that a particular feature, structure orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present invention. Thus, appearancesof the phrases “in one embodiment” or “in an example” in various placesthroughout this specification are not necessarily all referring to thesame embodiment or example, but may. Furthermore, the particularfeatures, structures or characteristics may be combined in any suitablemanner, as would be apparent to one of ordinary skill in the art fromthis disclosure, in one or more embodiments.

Similarly it should be appreciated that in the above description ofexemplary embodiments of the invention, various features of theinvention are sometimes grouped together in a single embodiment, figure,or description thereof for the purpose of streamlining the disclosureand aiding in the understanding of one or more of the various inventiveaspects. This method of disclosure, however, is not to be interpreted asreflecting an intention that the claimed invention requires morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Any claimsfollowing the Detailed Description are hereby expressly incorporatedinto this Detailed Description, with each claim standing on its own as aseparate embodiment of this invention.

Unless specifically stated otherwise, as apparent from the followingdiscussions, it is appreciated that throughout the specificationdiscussions utilizing terms such as “processing,” “computing,”“calculating,” “determining” or the like, refer to the action and/orprocesses of a microprocessor, controller or computing system, orsimilar electronic computing or signal processing device, thatmanipulates and/or transforms data.

Furthermore, while some embodiments described herein include some butnot other features included in other embodiments, combinations offeatures of different embodiments are meant to be within the scope ofthe invention, and form different embodiments, as would be understood bythose in the art. For example, in the following claims, any of theclaimed embodiments can be used in any combination.

Thus, while there has been described what are believed to be thepreferred embodiments of the invention, those skilled in the art willrecognize that other and further modifications may be made theretowithout departing from the scope of the invention, and it is intended toclaim all such changes and modifications as fall within the scope of theinvention.

While the present invention has been disclosed with reference toparticular details of construction, these should be understood as havingbeen provided by way of example and not as limitations to the scope ofthe invention.

What is claimed is:
 1. A seam wand device for beverages, comprising: a metallic main body tube; a steam hose that passes through the tube; the tube also passing through a flexible spacer that is within the tube.
 2. The device of claim 1, wherein: the spacer extends along the entire of an internal extent of the hose.
 3. The device of either of claim 1 or 2, wherein: the spacer is a coil.
 4. The device of either of claim 1 or 2, wherein: the spacer is a polymeric sleeve.
 5. A steam wand device for beverages, comprising: a main body tube having a metallic primary tube and a metallic tip; the primary tube and the tip being attached to one another by a polymeric steam nozzle; the nozzle having a central bone that extends from an inlet adjacent to a lower end of a steam hose to an exit opening.
 6. The device of claim 5, wherein: a lower end of the primary tube and an upper end of the tip are internally threaded to cooperate with external threads on the nozzle.
 7. The device of claim 6, wherein: the external threads on the nozzle are formed between an inlet to the nozzle and the exit opening.
 8. The device of any one of claims 5-7, wherein: the nozzle protrudes beyond a lowest part of the tip.
 9. The device of claim 5, wherein: the lower end of the stream hose is retained inside a tip connector that cooperates with a hollow rivet that is fitted to the lower end of the steam hose.
 10. The device of claim 9, wherein: the tip connector is carried within a recess in a hose connector.
 11. The device of claim 10, wherein: a lower part of the hose connector receives an upper part of the steam nozzle.
 12. The device of claim 10, wherein: a seal is interposed between the upper part of the steam nozzle and the hose connector.
 13. The device of claim 5, wherein: the nozzle cooperates with a hose connector that receives a tip connector that is attached to the hose; the hose connector having a slot for accessing a “C” clip that retains a tip connector that is carried by the hose.
 14. The device of claim 5, wherein: the nozzle has an external flange; nozzle/seals being carried by grooves that are located on upper and a lower side of the flange.
 15. The device of claim 14, wherein: each groove is located between the flange and a threaded portion. 